Yep, sorry, I wasn't very clear with that answer. I'll try and explain it better. The 1/2-tons use a frame that gets wider as it goes towards the back. The 3/4 and bigger trucks use rails that run parallel to each other (roughly 36" apart)to make mounting different bodies easier. The 1/2-ton pedal mounting bracket is different from the bigger trucks. 1/2-tons use a cast bracket that bolts to the bellhousing with 3 bolts and the tranny with 2 more bolts. The master bolts right to this bracket. The clutch and brake pedals both pivot off this bracket, but from seperate shafts. The 2 tranny bolt bosses on the 3 spd. bracket extend in farther than on the 4-spd. bracket since the 4-spd. is a larger tranny. The 3/4 and larger trucks have a common shaft for both pedals, and don't use the 1/2-ton bracket. There is one hole in the end of the shaft and a small bracket with 2 more holes to bolt into the bellhousing. These pedals are different from 1/2-ton pedals. Both pedals are bent different from the 1/2-tonners and the brake pedal has ears for the m/c pull-rod that runs to the master bell crank. Clutch pedal still has a hook on the bottom on both. The big truck master bolts to a bracket mounted to the frame.(remember these frame rails are straight, so all the linkage runs parallel to the rails) The 1/2-ton master hangs from the same bracket the pedals are on and doesn't use the bellcrank and linkage, just a pushrod.
